Researchers are looking for 1,200 pregnant women who already have a child with autism to participate in one of the largest studies ever conducted to identify early risk factors of autism spectrum disorders.

The study called the Early Autism Risk Longitudinal Investigation, or EARLI, will follow families through pregnancy, birth and the baby’s first three years. Researchers will be looking at genetic and environmental factors in pregnant mothers and their babies to help identify what causes autism.

Mothers who are currently pregnant are now being recruited by researchers at sites in Baltimore, Philadelphia, San Francisco, and Sacramento, Calif. In order to qualify for the study, families must already have a child with an autism spectrum disorder.

Researchers are also looking to be in touch with young families who have a child with autism who are not currently, but may become pregnant in the next couple of years. That’s because researchers will continue to accept families into the study for the next four years and they hope to enroll families as early in the pregnancy as possible.

Once enrolled in the study, researchers plan to meet with mothers three times during pregnancy and then visit the baby at 6, 12, 18, 24 and 36 months. Mothers will be asked to keep a diary during pregnancy. Plus, researchers will collect biological samples from the mother and child like blood, urine, hair and breast milk.

Aside from genetic information, they will be looking at environmental factors like diet and lifestyle, items in the home like pesticides, heavy metals, chemicals in cleaning products and flame retardants found in mattresses and other furniture. They will also consider any vaccines a child receives.

“The really unique thing about this study is that we’re identifying this information in real time,” says Lisa Croen, an epidemiologist at Kaiser Permanente, who is the principal investigator at the San Francisco study site. Previous studies have relied on the memories of family members to recall events prior to an autism diagnosis.

While the likelihood of a second child with autism being born to a family that already has a child with the disorder is unclear, researchers say they anticipate about 10 percent of the babies in the study will ultimately be diagnosed with autism.

The EARLI study is being funded by $14 million from the National Institutes of Health and $2.5 million from Autism Speaks. It is expected to take eight years to complete.

For more information about the EARLI study click here.